Herer's an 1939 Elswick 24LR LIght Roadster with the sloping top tube. I've also. see it on a Humber Light Roadster from the same era but it had a proprietary chainwheel, whereas the the OP's bicycle and the Elswick appears to be a Williams pattern. If so, there should be a date code on the crankarm and/ot chainwheel.